Superconducting traveling-wave parametric amplifier
AssigneeSeeQC, Inc.
InventorsAlessandro Miano, Oleg Mukhanov
Life of this patent
Estimating the term…
Abstract
A system and method are disclosed for a superconducting traveling-wave parametric amplifier (TWPA) with improved control and performance. In a preferred embodiment, the amplifier comprises an integrated array of symmetric rf-SQUIDs in a transmission line structure. A device was fabricated using niobium superconducting integrated circuits, and confirmed predicted performance, with a maximum gain up to 17 dB and a bandwidth of 4 GHz. A similar device can be applied as a low-noise, low-dissipation microwave amplifier for output from a superconducting quantum computer, or as a preamplifier, switch, or frequency converter for a sensitive microwave receiver, or as an output amplifier for a frequency-multiplexed superconducting detector array.
Claims19
A microwave amplifier system, comprising:
- an input port configured to receive a microwave signal;
- a plurality of microwave amplifiers in series being connected to receive the microwave signal, each microwave amplifier comprising at least one active element, a shunt capacitor, and a serial inductor, having an inductance which is a nonlinear function of a total signal in the serial inductor;
- a control port, configured to receive a signal which modulates the total signal in at least one serial inductor;
- and
- an output port, configured to present an amplified representation of the received microwave signal from the plurality of microwave amplifiers in series,
- wherein each microwave amplifier comprises a pair of shunted Josephson junctions forming a central loop, and an independent inductive loop for each Josephson junction, each independent inductive loop being inductively coupled to a control line, an input to the microwave amplifier being formed in the central loop between the pair of shunted Josephson junctions on a first side, and an output from the microwave amplifier being formed in the central loop between the pair of shunted Josephson junctions on a second side, having a shunt capacitor on the second side.
A method of amplifying a microwave signal, comprising:
- receiving a microwave signal;
- receiving a control input;
- processing the microwave signal with a plurality of microwave amplifiers in series, each microwave amplifier comprising a tunable microwave stage, comprising:
- a signal input configured to receive the microwave signal;
- an amplifier comprising a radio frequency superconducting quantum interference device (rf-SQUID) comprising a pair of shunted Josephson junctions, each Josephson junction having an associated inductive loop, wherein an effective inductance of the inductive loop is dependent on a total signal in the inductive loop dependent on an input to the rf-SQUID and the control signal inductively coupled to the inductive loop;
- a shunt capacitor at an output of the rf-SQUID;
- and
- an output configured to present an amplified representation of the microwave signal from the tunable microwave stage;
- modulating the total signal in at least one inductive loop with the received control signal;
- and
- outputting an amplified representation of the received microwave signal from the plurality of tunable microwave stages in series.
A tunable microwave device, comprising:
- a signal input configured to receive a microwave signal;
- a control input;
- an amplifier comprising a radio frequency superconducting quantum interference device (rf-SQUID) comprising a pair of shunted Josephson junctions, each Josephson junction having an associated inductive loop, wherein an effective inductance of the inductive loop is dependent on a total signal in the inductive loop dependent on an input to the rf-SQUID and the control signal inductively coupled to the inductive loop;
- a shunt capacitor at an output of the rf-SQUID;
- and
- an output configured to present an amplified representation of the microwave signal.
Dependencies are inferred from the claim text.